<!DOCTYPE html>
<html>
 <head>
 	<meta charset="utf8"/>
 	<title>打开摄像头测试</title>
 </head>
 <body>
    <h1>摄像头测试<h1>
    <div id="app">
         <video autoplay controls id="video"></video>
    </div>
    <button id="cameraBtn">打开摄像头测试</button>
 </body>
</html>

<script type="text/javascript">
  document.querySelector('#cameraBtn').onclick = function() {
  	let constraints ={ audio: true, video: true };
  	navigator.mediaDevices.getUserMedia(constraints).then(function(stream) {
  		document.querySelector('#video').srcObject = stream
  	}).catch(function(err) {
  		console.log(err.name+":"+err.message);
  	});
  }


</script>

